In the telecommunications network's classic structure, intelligence resides in the internals of the individual switching systems within the network. In this structure when a telecommunications operating company needs to evolve their network, keep up with standards or differentiate their products, they usually contract with the vendor of the switching equipment for new switch-based development. While this is excellent business for the switching equipment vendor, it requires the operating company to be locked into the particular vendor's delivery schedule and quality of output. With the complexity of switch-based software continually growing, updates and changes to the software required to implement a new service (or modify existing services) are taking longer to complete, and often degrades the quality of the processing. In the rapidly changing telecommunication marketplace success has a lot to do with introducing services quickly and with exceptional quality. Two existing enhancements to the classic telecommunications network help give the operating company independence from the switch vendors and improve service deployment. These include (1) Intelligent Networking (IN) or Advanced Intelligent Networking (AIN) and (2) programmable switching matrices.
Intelligent Networking is driven by standards that have defined (and include) components such as Service Control Points (SCP) and Service Switching Points (SSP) communicating via a common channel signaling system 7 (CCS7) infrastructure. The IN components and standards decouple service development from internal switch implementation and allows an operating company to develop services in isolation of the switch vendors' development and deployment schedules. The benefits of these standards and the resulting changes to the network architecture are that services can be written independently from the switch, implemented by third-parties or the operating company themselves, and work with switches manufactured by different vendors. The disadvantages of IN, however, are that the standards have been slow to evolve and the complexity is high thus requiring a phased implementation from switch vendors, and the functionality defined by the CCS7 messaging (e.g., TCAP) leaves little room for differentiation of service offerings.
Taking advantage of the slowness in which the IN standards have been defined, implemented and deployed in the switching network, some telephony equipment vendors have implemented stand-alone programmable switching matrices. These products have been used to prototype and deploy services into the public switch network. Examples of such services include voice dialing, televoting, and debit card services. These stand-alone systems are connected as a terminal appliance, typically via integrated services data network (ISDN), primary rate interfacing (PRI) or T1 connections, onto the existing backbone network as service overlay networks.
The advantages of stand-alone programmable switching matrices are the same as with the IN but there are several disadvantages. The standalone programmable switching matrices do not offer the reliability or the capacity required for optimal network implementation. Additionally, the different computing platforms added into the network to support these overlay systems introduce maintenance and network management complexities resulting in high operations and sustaining costs. Lastly, with these stand-alone overlay programmable switching matrices there is an inefficient use of resources as both systems are tied up for the duration of the service.